Internet of Things (IoT) 2025 – 400 Free Practice Questions to Pass the Exam

The validity of an IP address depends on the numerical constraints of its octets. In the context of IPv4 addresses, each octet must be a number between 0 and 255. The address in question, which includes the octet '256', exceeds this upper limit, rendering the entire IP address invalid.

The other choices represent valid IP addresses because all their octets fall within the permissible range:

- The first address, 43.126.38.91, has octets of 43, 126, 38, and 91, all of which are within the 0-255 range.

- The second address, 126.133.254.1, has octets of 126, 133, 254, and 1, also within the valid range.

- The last address, 222.222.222.222, has all octets equal to 222, which is again within the accepted range.

Thus, the only invalid address among the provided options is the one with '256', since it does not comply with the defined structure for valid octet ranges in IPv4.